/*
 * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.bpmn.helper;

import com.fasterxml.jackson.databind.node.ObjectNode;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map;
import org.activiti.bpmn.model.FlowElement;
import org.activiti.bpmn.model.MapExceptionEntry;
import org.activiti.bpmn.model.Task;
import org.activiti.engine.ActivitiException;
import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.DynamicBpmnConstants;
import org.activiti.engine.delegate.BpmnError;
import org.activiti.engine.delegate.CustomPropertiesResolver;
import org.activiti.engine.delegate.DelegateExecution;
import org.activiti.engine.delegate.DelegateTask;
import org.activiti.engine.delegate.ExecutionListener;
import org.activiti.engine.delegate.Expression;
import org.activiti.engine.delegate.JavaDelegate;
import org.activiti.engine.delegate.TaskListener;
import org.activiti.engine.delegate.TransactionDependentExecutionListener;
import org.activiti.engine.delegate.TransactionDependentTaskListener;
import org.activiti.engine.impl.bpmn.behavior.AbstractBpmnActivityBehavior;
import org.activiti.engine.impl.bpmn.behavior.ServiceTaskJavaDelegateActivityBehavior;
import org.activiti.engine.impl.bpmn.parser.FieldDeclaration;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.delegate.ActivityBehavior;
import org.activiti.engine.impl.delegate.SubProcessActivityBehavior;
import org.activiti.engine.impl.delegate.TriggerableActivityBehavior;
import org.activiti.engine.impl.delegate.invocation.ExecutionListenerInvocation;
import org.activiti.engine.impl.delegate.invocation.TaskListenerInvocation;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.util.ReflectUtil;
import org.apache.commons.lang3.StringUtils;

/**
 * Helper class for bpmn constructs that allow class delegation.
 *
 * This class will lazily instantiate the referenced classes when needed at runtime.
 *




 */
public class ClassDelegate
    extends AbstractBpmnActivityBehavior
    implements
        TaskListener,
        ExecutionListener,
        TransactionDependentExecutionListener,
        TransactionDependentTaskListener,
        SubProcessActivityBehavior,
        CustomPropertiesResolver {

    private static final long serialVersionUID = 1L;

    protected String serviceTaskId;
    protected String className;
    protected List<FieldDeclaration> fieldDeclarations;
    protected ExecutionListener executionListenerInstance;
    protected TransactionDependentExecutionListener transactionDependentExecutionListenerInstance;
    protected TaskListener taskListenerInstance;
    protected TransactionDependentTaskListener transactionDependentTaskListenerInstance;
    protected ActivityBehavior activityBehaviorInstance;
    protected Expression skipExpression;
    protected List<MapExceptionEntry> mapExceptions;
    protected CustomPropertiesResolver customPropertiesResolverInstance;

    public ClassDelegate(String className, List<FieldDeclaration> fieldDeclarations, Expression skipExpression) {
        this.className = className;
        this.fieldDeclarations = fieldDeclarations;
        this.skipExpression = skipExpression;
    }

    public ClassDelegate(
        String id,
        String className,
        List<FieldDeclaration> fieldDeclarations,
        Expression skipExpression,
        List<MapExceptionEntry> mapExceptions
    ) {
        this(className, fieldDeclarations, skipExpression);
        this.serviceTaskId = id;
        this.mapExceptions = mapExceptions;
    }

    public ClassDelegate(String className, List<FieldDeclaration> fieldDeclarations) {
        this(className, fieldDeclarations, null);
    }

    public ClassDelegate(Class<?> clazz, List<FieldDeclaration> fieldDeclarations) {
        this(clazz.getName(), fieldDeclarations, null);
    }

    public ClassDelegate(Class<?> clazz, List<FieldDeclaration> fieldDeclarations, Expression skipExpression) {
        this(clazz.getName(), fieldDeclarations, skipExpression);
    }

    // Execution listener
    @Override
    public void notify(DelegateExecution execution) {
        if (executionListenerInstance == null) {
            executionListenerInstance = getExecutionListenerInstance();
        }
        Context.getProcessEngineConfiguration()
            .getDelegateInterceptor()
            .handleInvocation(new ExecutionListenerInvocation(executionListenerInstance, execution));
    }

    // Transaction Dependent execution listener
    @Override
    public void notify(
        String processInstanceId,
        String executionId,
        FlowElement flowElement,
        Map<String, Object> executionVariables,
        Map<String, Object> customPropertiesMap
    ) {
        if (transactionDependentExecutionListenerInstance == null) {
            transactionDependentExecutionListenerInstance = getTransactionDependentExecutionListenerInstance();
        }

        // Note that we can't wrap it in the delegate interceptor like usual here due to being executed when the context is already removed.
        transactionDependentExecutionListenerInstance.notify(
            processInstanceId,
            executionId,
            flowElement,
            executionVariables,
            customPropertiesMap
        );
    }

    @Override
    public Map<String, Object> getCustomPropertiesMap(DelegateExecution execution) {
        if (customPropertiesResolverInstance == null) {
            customPropertiesResolverInstance = getCustomPropertiesResolverInstance();
        }
        return customPropertiesResolverInstance.getCustomPropertiesMap(execution);
    }

    // Task listener
    @Override
    public void notify(DelegateTask delegateTask) {
        if (taskListenerInstance == null) {
            taskListenerInstance = getTaskListenerInstance();
        }
        try {
            Context.getProcessEngineConfiguration()
                .getDelegateInterceptor()
                .handleInvocation(new TaskListenerInvocation(taskListenerInstance, delegateTask));
        } catch (Exception e) {
            throw new ActivitiException("Exception while invoking TaskListener: " + e.getMessage(), e);
        }
    }

    @Override
    public void notify(
        String processInstanceId,
        String executionId,
        Task task,
        Map<String, Object> executionVariables,
        Map<String, Object> customPropertiesMap
    ) {
        if (transactionDependentTaskListenerInstance == null) {
            transactionDependentTaskListenerInstance = getTransactionDependentTaskListenerInstance();
        }
        transactionDependentTaskListenerInstance.notify(
            processInstanceId,
            executionId,
            task,
            executionVariables,
            customPropertiesMap
        );
    }

    protected ExecutionListener getExecutionListenerInstance() {
        Object delegateInstance = instantiateDelegate(className, fieldDeclarations);
        if (delegateInstance instanceof ExecutionListener) {
            return (ExecutionListener) delegateInstance;
        } else if (delegateInstance instanceof JavaDelegate) {
            return new ServiceTaskJavaDelegateActivityBehavior((JavaDelegate) delegateInstance);
        } else {
            throw new ActivitiIllegalArgumentException(
                delegateInstance.getClass().getName() +
                " doesn't implement " +
                ExecutionListener.class +
                " nor " +
                JavaDelegate.class
            );
        }
    }

    protected TransactionDependentExecutionListener getTransactionDependentExecutionListenerInstance() {
        Object delegateInstance = instantiateDelegate(className, fieldDeclarations);
        if (delegateInstance instanceof TransactionDependentExecutionListener) {
            return (TransactionDependentExecutionListener) delegateInstance;
        } else {
            throw new ActivitiIllegalArgumentException(
                delegateInstance.getClass().getName() +
                " doesn't implement " +
                TransactionDependentExecutionListener.class
            );
        }
    }

    protected CustomPropertiesResolver getCustomPropertiesResolverInstance() {
        Object delegateInstance = instantiateDelegate(className, fieldDeclarations);
        if (delegateInstance instanceof CustomPropertiesResolver) {
            return (CustomPropertiesResolver) delegateInstance;
        } else {
            throw new ActivitiIllegalArgumentException(
                delegateInstance.getClass().getName() + " doesn't implement " + CustomPropertiesResolver.class
            );
        }
    }

    protected TaskListener getTaskListenerInstance() {
        Object delegateInstance = instantiateDelegate(className, fieldDeclarations);
        if (delegateInstance instanceof TaskListener) {
            return (TaskListener) delegateInstance;
        } else {
            throw new ActivitiIllegalArgumentException(
                delegateInstance.getClass().getName() + " doesn't implement " + TaskListener.class
            );
        }
    }

    protected TransactionDependentTaskListener getTransactionDependentTaskListenerInstance() {
        Object delegateInstance = instantiateDelegate(className, fieldDeclarations);
        if (delegateInstance instanceof TransactionDependentTaskListener) {
            return (TransactionDependentTaskListener) delegateInstance;
        } else {
            throw new ActivitiIllegalArgumentException(
                delegateInstance.getClass().getName() + " doesn't implement " + TransactionDependentTaskListener.class
            );
        }
    }

    // Activity Behavior
    public void execute(DelegateExecution execution) {
        boolean isSkipExpressionEnabled = SkipExpressionUtil.isSkipExpressionEnabled(execution, skipExpression);
        if (
            !isSkipExpressionEnabled ||
            (isSkipExpressionEnabled && !SkipExpressionUtil.shouldSkipFlowElement(execution, skipExpression))
        ) {
            if (Context.getProcessEngineConfiguration().isEnableProcessDefinitionInfoCache()) {
                ObjectNode taskElementProperties = Context.getBpmnOverrideElementProperties(
                    serviceTaskId,
                    execution.getProcessDefinitionId()
                );
                if (
                    taskElementProperties != null &&
                    taskElementProperties.has(DynamicBpmnConstants.SERVICE_TASK_CLASS_NAME)
                ) {
                    String overrideClassName = taskElementProperties
                        .get(DynamicBpmnConstants.SERVICE_TASK_CLASS_NAME)
                        .asText();
                    if (StringUtils.isNotEmpty(overrideClassName) && !overrideClassName.equals(className)) {
                        className = overrideClassName;
                        activityBehaviorInstance = null;
                    }
                }
            }

            if (activityBehaviorInstance == null) {
                activityBehaviorInstance = getActivityBehaviorInstance();
            }

            try {
                activityBehaviorInstance.execute(execution);
            } catch (BpmnError error) {
                ErrorPropagation.propagateError(error, execution);
            } catch (RuntimeException e) {
                if (!ErrorPropagation.mapException(e, (ExecutionEntity) execution, mapExceptions)) throw e;
            }
        }
    }

    // Signallable activity behavior
    public void trigger(DelegateExecution execution, String signalName, Object signalData) {
        if (activityBehaviorInstance == null) {
            activityBehaviorInstance = getActivityBehaviorInstance();
        }

        if (activityBehaviorInstance instanceof TriggerableActivityBehavior) {
            ((TriggerableActivityBehavior) activityBehaviorInstance).trigger(execution, signalName, signalData);
        } else {
            throw new ActivitiException(
                "signal() can only be called on a " + TriggerableActivityBehavior.class.getName() + " instance"
            );
        }
    }

    // Subprocess activityBehaviour

    @Override
    public void completing(DelegateExecution execution, DelegateExecution subProcessInstance) throws Exception {
        if (activityBehaviorInstance == null) {
            activityBehaviorInstance = getActivityBehaviorInstance();
        }

        if (activityBehaviorInstance instanceof SubProcessActivityBehavior) {
            ((SubProcessActivityBehavior) activityBehaviorInstance).completing(execution, subProcessInstance);
        } else {
            throw new ActivitiException(
                "completing() can only be called on a " + SubProcessActivityBehavior.class.getName() + " instance"
            );
        }
    }

    @Override
    public void completed(DelegateExecution execution) throws Exception {
        if (activityBehaviorInstance == null) {
            activityBehaviorInstance = getActivityBehaviorInstance();
        }

        if (activityBehaviorInstance instanceof SubProcessActivityBehavior) {
            ((SubProcessActivityBehavior) activityBehaviorInstance).completed(execution);
        } else {
            throw new ActivitiException(
                "completed() can only be called on a " + SubProcessActivityBehavior.class.getName() + " instance"
            );
        }
    }

    protected ActivityBehavior getActivityBehaviorInstance() {
        Object delegateInstance = instantiateDelegate(className, fieldDeclarations);

        if (delegateInstance instanceof ActivityBehavior) {
            return determineBehaviour((ActivityBehavior) delegateInstance);
        } else if (delegateInstance instanceof JavaDelegate) {
            return determineBehaviour(new ServiceTaskJavaDelegateActivityBehavior((JavaDelegate) delegateInstance));
        } else {
            throw new ActivitiIllegalArgumentException(
                delegateInstance.getClass().getName() +
                " doesn't implement " +
                JavaDelegate.class.getName() +
                " nor " +
                ActivityBehavior.class.getName()
            );
        }
    }

    // Adds properties to the given delegation instance (eg multi instance) if
    // needed
    protected ActivityBehavior determineBehaviour(ActivityBehavior delegateInstance) {
        if (hasMultiInstanceCharacteristics()) {
            multiInstanceActivityBehavior.setInnerActivityBehavior((AbstractBpmnActivityBehavior) delegateInstance);
            return multiInstanceActivityBehavior;
        }
        return delegateInstance;
    }

    protected Object instantiateDelegate(String className, List<FieldDeclaration> fieldDeclarations) {
        return ClassDelegate.defaultInstantiateDelegate(className, fieldDeclarations);
    }

    // --HELPER METHODS (also usable by external classes)
    // ----------------------------------------

    public static Object defaultInstantiateDelegate(Class<?> clazz, List<FieldDeclaration> fieldDeclarations) {
        return defaultInstantiateDelegate(clazz.getName(), fieldDeclarations);
    }

    public static Object defaultInstantiateDelegate(String className, List<FieldDeclaration> fieldDeclarations) {
        Object object = ReflectUtil.instantiate(className);
        applyFieldDeclaration(fieldDeclarations, object);
        return object;
    }

    public static void applyFieldDeclaration(List<FieldDeclaration> fieldDeclarations, Object target) {
        applyFieldDeclaration(fieldDeclarations, target, true);
    }

    public static void applyFieldDeclaration(
        List<FieldDeclaration> fieldDeclarations,
        Object target,
        boolean throwExceptionOnMissingField
    ) {
        if (fieldDeclarations != null) {
            for (FieldDeclaration declaration : fieldDeclarations) {
                applyFieldDeclaration(declaration, target, throwExceptionOnMissingField);
            }
        }
    }

    public static void applyFieldDeclaration(FieldDeclaration declaration, Object target) {
        applyFieldDeclaration(declaration, target, true);
    }

    public static void applyFieldDeclaration(
        FieldDeclaration declaration,
        Object target,
        boolean throwExceptionOnMissingField
    ) {
        Method setterMethod = ReflectUtil.getSetter(
            declaration.getName(),
            target.getClass(),
            declaration.getValue().getClass()
        );

        if (setterMethod != null) {
            try {
                setterMethod.invoke(target, declaration.getValue());
            } catch (IllegalArgumentException e) {
                throw new ActivitiException(
                    "Error while invoking '" + declaration.getName() + "' on class " + target.getClass().getName(),
                    e
                );
            } catch (IllegalAccessException e) {
                throw new ActivitiException(
                    "Illegal acces when calling '" +
                    declaration.getName() +
                    "' on class " +
                    target.getClass().getName(),
                    e
                );
            } catch (InvocationTargetException e) {
                throw new ActivitiException(
                    "Exception while invoking '" + declaration.getName() + "' on class " + target.getClass().getName(),
                    e
                );
            }
        } else {
            Field field = ReflectUtil.getField(declaration.getName(), target);
            if (field == null) {
                if (throwExceptionOnMissingField) {
                    throw new ActivitiIllegalArgumentException(
                        "Field definition uses unexisting field '" +
                        declaration.getName() +
                        "' on class " +
                        target.getClass().getName()
                    );
                } else {
                    return;
                }
            }

            // Check if the delegate field's type is correct
            if (!fieldTypeCompatible(declaration, field)) {
                throw new ActivitiIllegalArgumentException(
                    "Incompatible type set on field declaration '" +
                    declaration.getName() +
                    "' for class " +
                    target.getClass().getName() +
                    ". Declared value has type " +
                    declaration.getValue().getClass().getName() +
                    ", while expecting " +
                    field.getType().getName()
                );
            }
            ReflectUtil.setField(field, target, declaration.getValue());
        }
    }

    public static boolean fieldTypeCompatible(FieldDeclaration declaration, Field field) {
        if (declaration.getValue() != null) {
            return field.getType().isAssignableFrom(declaration.getValue().getClass());
        } else {
            // Null can be set any field type
            return true;
        }
    }

    /**
     * returns the class name this {@link ClassDelegate} is configured to. Comes in handy if you want to check which delegates you already have e.g. in a list of listeners
     */
    public String getClassName() {
        return className;
    }
}
